What Coke Contains

The H-E-B grocery store a mile from my home in Austin, Texas, sells twelve cans of Coca-Cola for $4.49.

Each one of those cans originated in a small town of four thousand people on the Murray River in Western Australia called Pinjarra—the site of the world’s largest bauxite mine. Bauxite is surface-mined— basically scraped and dug from the top of the ground—and then crushed and washed with hot sodium hydroxide until it separates into aluminum hydroxide and a waste material called “red mud.” The aluminum hydroxide is first cooled and then heated to over a thousand degrees Celsius in a kiln, where it becomes aluminum oxide, or alumina. The alumina is dissolved in a molten substance called cryolite, a rare mineral first discovered in Greenland, and turned into pure aluminum using electricity in a process called electrolysis. The pure aluminum sinks to the bottom of the molten cryolite, is drained off, and is placed in a mold. The result is a long, cylindrical bar of aluminum. Australia’s role in the process ends here. The bar is transported west to the port of Bunbury and loaded onto a container ship to begin a month-long journey to—in the case of Coke for sale in Austin—the port of Corpus Christi, on the Texan coast.

After the aluminum bar makes landfall, a truck takes it north on Interstates 37 and 35 to a bottling plant on Burnet Road in Austin, where it is rolled flat in a rolling mill and turned into aluminum sheets. The sheets are punched into circles and shaped into a cup by a mechanical process called drawing and ironing—this not only forms the can but also thins the aluminum. The transition from circle to cylinder takes about a fifth of a second. The outside of the can is decorated using a base layer called “urethane acrylate,” then up to seven layers of colored acrylic paint and varnish, which are cured using ultraviolet light. The inside of the can is painted, too—with a chemical called a “comestible polymeric coating,” to prevent aluminum from getting into the soda. So far, this vast tool chain has produced only an empty can with no lid. The next step is to fill it up.

Coca-Cola is made from syrup produced by the Coca-Cola Company of Atlanta, Georgia. The syrup is the only thing the Coca-Cola Company provides; the bottling operation belongs to a separate, independent corporation called the Coca-Cola Bottling Company. The main ingredient in the syrup used in the United States is a sweetener called high-fructose corn syrup 55, so named because it is 55 percent fructose, or “fruit sugar,” and 42 percent glucose, or “simple sugar”— the same ratio of fructose to glucose as in natural honey. High-fructose corn syrup is made by grinding wet corn until it becomes cornstarch, mixing the cornstarch with an enzyme secreted by a bacillus, a rod- shaped bacterium, and another enzyme, this one secreted by an aspergillus mold, and then using a third enzyme, xylose isomerase, derived from a bacterium called Streptomyces rubiginosus, to turn some of the glucose into fructose.

The second ingredient, caramel coloring, gives the drink its distinctive dark brown color. There are four types of caramel coloring; Coca-Cola uses type E150d, which is made by heating sugars with sulfite and ammonia to create bitter brown liquid. The syrup’s other principal ingredient is phosphoric acid, which adds acidity and is made by diluting burnt phosphorus (created by heating phosphate rock in an arc furnace) and processing it to remove arsenic.

High-fructose corn syrup and caramel coloring make up most of the syrup, but all they add is sweetness and color. Flavors make up a much smaller proportion of the mixture. These include vanilla, which—as we have already seen—is the fruit of a Mexican orchid that has been dried and cured; cinnamon, which is the inner bark of a Sri Lankan tree; coca leaf, which comes from South America and is processed in a unique U.S. government–authorized factory in New Jersey to remove its addictive stimulant, cocaine; and kola nut, a red nut found on a tree that grows in the African rain forest (this may be the origin of Coca- Cola’s distinctive red logo).

The final ingredient, caffeine, is a stimulating alkaloid that can be derived from the kola nut, coffee beans, and other sources.

All these ingredients are combined and boiled down to a concentrate, which is transported from the Coca-Cola Company factory in Atlanta to the Coca-Cola Bottling Company factory in Austin, where it is diluted with local water infused with carbon dioxide. Some of the carbon dioxide turns to gas in the water, and these gas bubbles give the water effervescence, also known as “fizz,” after its sound. The final mixture is poured into cans, which still need lids.

The top of the can is carefully engineered: it is aluminum, too, but it has to be thicker and stronger than the rest of the can to withstand the pressure of the carbon dioxide gas, and so it is made from an alloy with more magnesium. The lid is punched and scored, and a tab open- ing, also made of aluminum, is installed. The finished lid is put on top of the filled can, and the edges of the can are folded over it and welded shut. Twelve of these cans are packaged into a paperboard box called a fridge pack, using a machine capable of producing three hundred such packs a minute.

Coca-Cola did not teach the world to sing, no matter what its commercials suggest, yet every can contains humanity’s choir.

The finished box is transported by road to my local H-E-B grocery store, where—finally—it can be bought, taken home, chilled, and consumed. This chain, which spans bauxite bulldozers, refrigerators, urethane, bacteria, and cocaine, and touches every continent on the planet except Antarctica, produces seventy million cans of Coca-Cola each day, one of which can be purchased for about a dollar on some close- by street corner, and each of which contains far more than something to drink. Like every other creation, a can of Coke is a product of our world entire and contains inventions that trace all the way back to the origins of our species.

The number of individuals who know how to make a can of Coke is zero. The number of individual nations that could produce a can of Coke is zero. This famously American product is not American at all. Invention and creation, as we have seen, is something we are all in together. Modern tool chains are so long and complex that they bind us into one people and one planet. They are chains of minds: local and foreign, ancient and modern, living and dead—the result of disparate invention and intelligence distributed over time and space. Coca-Cola did not teach the world to sing, no matter what its commercials suggest, yet every can contains humanity’s choir.

“What Coke Contains” is an extract from “How to Fly a Horse .” It first appeared in Medium.

After “What Coke Contains” was first published, many people mentioned similar — and better — work that I did not know about and is well worth reading:

” I, Pencil,” a classic essay by Leonard E. Read (thank you, Chuck Grimmett of the Foundation For Economic Education, Bryce Miller and Michael Joseph.) Tom Snyder maintains a great web site about this essay.

”Life Of The Automobile,” [LINK: http://amzn.to/12pyQXj] by Ilya Ehrenburg (thank you, John Glover of Bloomberg News.)

A 1967 Christmas Sermon by Martin Luther King, which says, “before you finish eating breakfast in the morning, you’ve depended on more than half of the world.” (Thank you, Ben Glickman of ESL101.)

The excellent, “The Toaster Project,” by Thomas Thwaites, which I read long after I wrote this piece, and had not considered in this context until Nick Douglas, Editor of Slacktory, pointed out the similarity. Thank you, Nick.